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About Science Prof OnlineScience Prof Online PowerPoint Resources Science Prof Online (SPO) is a free science education website that provides fully-developed.

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Presentation on theme: "About Science Prof OnlineScience Prof Online PowerPoint Resources Science Prof Online (SPO) is a free science education website that provides fully-developed."— Presentation transcript:

1 About Science Prof OnlineScience Prof Online PowerPoint Resources Science Prof Online (SPO) is a free science education website that provides fully-developed Virtual Science Classrooms, science-related PowerPoints, articles and images. The site is designed to be a helpful resource for students, educators, and anyone interested in learning about science. The SPO Virtual Classrooms offer many educational resources, including practice test questions, review questions, lecture PowerPoints, video tutorials, sample assignments and course syllabi. New materials are continually being developed, so check back frequently, or follow us on Facebook (Science Prof Online) or Twitter (ScienceProfSPO) for updates. Many SPO PowerPoints are available in a variety of formats, such as fully editable PowerPoint files, as well as uneditable versions in smaller file sizes, such as PowerPoint Shows and Portable Document Format (.pdf), for ease of printing. Images used on this resource, and on the SPO website are, wherever possible, credited and linked to their source. Any words underlined and appearing in blue are links that can be clicked on for more information. PowerPoints must be viewed in slide show mode to use the hyperlinks directly. Several helpful links to fun and interactive learning tools are included throughout the PPT and on the Smart Links slide, near the end of each presentation. You must be in slide show mode to utilize hyperlinks and animations. This digital resource is licensed under Creative Commons Attribution-ShareAlike 3.0: Alicia Cepaitis, MS Chief Creative Nerd Science Prof Online Online Education Resources, LLC From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com Image: Compound microscope objectives, T. Port Tami Port, MS Creator of Science Prof Online Chief Executive Nerd Science Prof Online Online Education Resources, LLC

2 From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com Images: Ribbon diagram of enzyme with cofactorenzyme with cofactor; Enzymatic reaction, WikiEnzymatic reaction

3 Apple Experiment Come up and get an apple and a slice of lemon. When you get back to your seat: 1. Take a big bite of your delicious apple. 2. Immediately squeeze lemon juice over the apple flesh that is now exposed from the bite. 3. IMPORTANT! Don’t get lemon juice all over the apple. Make sure that it is ONLY on the area that you just bit! 4. Set the lemon aside and wipe any lemon juice off of your hands with a napkin. 5. Take another bite from the opposite side of your apple. 6. Set your apple aside. From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

4 How do you define living? Some characteristics of life … Organization Acquire and transform materials & energy Homeostasis Respond to stimuli Grow, develop & reproduce Adapt and evolve Image: Newly emerged Monarch Butterfly, T. Port From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

5 Metabolism The Transformation of Energy Sum of all chemical reactions in a cell or organism. Cells either get their energy either by photosynthesis or by eating stuff. Image: Autotrophs & Heterotrophs, Mikael HäggströmAutotrophs & Heterotrophs From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

6 Metabolic Pathways Series of chemical reactions that regulate the concentration of substances within the organism. Has order, like an assembly line. Molecules are altered in a series of steps. Use many smaller steps rather than one big step. Enzymes are workers that control each station along the pathway. May be turned on and off as needed. Video: Biochemical Pathways Image: Metabolism Pathways, WikiMetabolism Pathways From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

7 Why Are Enzymes So Important? Why are we devoting one whole lecture topic to a protein molecule? Nearly all chemical reactions in biological cells need enzymes to make the reaction occur fast enough to support life. Image: Jumping rope, Meagan E. KleinJumping rope From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

8 Digestion & Enzymes Image: Digestive system diagram, WikiDigestive system diagram Digesting one meal could take years without enzymes! Examples of digestive enzymes: sucrase, lipase, amylase. Videos: 1. Digestion of Molecules AnimationDigestion of Molecules Animation 2. A Look At Digestive Enzymes In Our BodyA Look At Digestive Enzymes In Our Body 3. Role of Enzymes in Digestion of FoodRole of Enzymes in Digestion of Food From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

9 What are enzymes? Enzymes are proteinsproteins. Tertiary an d quaternary structure. Image: Levels of protein structure, M RuizLevels of protein structure From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

10 What do enzymes do? Enzymes act as catalysts in cellular reactions. Q : What does a catalyst do? Images: Activation energy graph, WikiActivation energy graph From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

11 How do enzymes work? Enzymes catalyze reactions by weakening chemical bonds, which lowers activation energy. Image: Activation energy graph, WikiActivation energy graph Video: Activation Energy From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

12 How do enzymes work? Each enzyme has a unique 3-D shape, including a surface groove called an active site.enzyme The enzyme works by binding a specific chemical reactant ( substrate ) to its active site, causing the substrate to become unstable and react. The resulting product (s) is then released from the active site. Image: Enzymatic reaction, Jerry Crimson ManniEnzymatic reaction Video: How Enzymes WorkHow Enzymes Work From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

13 are specific for what they will catalyze. fit with substrate like a key and lock. Enzymes… From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

14 When an enzyme is interacting with it’s substrate, during the chemical reaction, together they are referred to as the … Image: Enzyme –substrate complex, UC DavisEnzyme –substrate complex From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

15 …are reusable. They are not consumed (used up) in the reactions they catalyze. May perform thousands of reactions per second. Enzymes… Video: Enzyme Hydrolysis of SucroseEnzyme Hydrolysis of Sucrose From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

16 The more cans (substrate), the more $ (product). The more recycling machines (enzymes), the faster the cans turn into $. Enzymes are like tiny machines that catalyze reactions within living things. $ $ $ $ $ $ $ From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

17 Enzymes… Have names that usually end in -ase. - Catalase - Protease - Lactase Image: Animation of Enzyme, WikiAnimation of Enzyme From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

18 Formats for writing an enzymatic reaction. ( ________ ) _______ + ________ > _________ ( ________ ) __________ > ________ ________ From the Virtual Cell Biology Classroom on ScienceProfOnline.comVirtual Cell Biology ClassroomScienceProfOnline.com

19 Q: How do you sabotage an enzyme? Irreversible egg protein denaturation caused by high temperature. Denature it! Alteration of a protein shape through some form of external stressprotein Example, by applying heat, acidic or alkaline environment Denatured enzyme can’t carry out its cellular function. Video: Denaturation in FoodDenaturation in Food From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

20 Factors That Influence Enzyme Activity Temperature pH Cofactors & Coenzymes Inhibitors Image: Animation of Enzyme, WikiAnimation of Enzyme From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

21 Temperature & pH Think about what kind of cell or organism an enzyme may work in… enzyme Temperatures far above the normal range denature enzymes. (This is why very high fevers are so dangerous. They can cook the body’s proteins.) Most enzymes work best near neutral pH (6 to 8). pH Images: pH scale, Edward Stevens, WikipH scale From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

22 Factors That Influence Enzyme Activity Temperature pH Cofactors & Coenzymes Inhibitors Image: Animation of Enzyme, WikiAnimation of Enzyme From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

23 Cofactors & Coenzymes substances (zinc, iron, copper, vitamins)Non-protein substances (zinc, iron, copper, vitamins) are sometimes need for proper enzymatic activity. Coenzyme vs Cofactor: What’s the difference? - Cofactor more general term. Includes inorganic and organic molecules.organic molecules - Coenzyme type of cofactor, But specifically organic molecules. Image: Enzyme with Cofactor, Wiki. Ribbon-diagram showing carbonic anhydrase II. The grey sphere is the zinc cofactor in the active site.Enzyme with Cofactor From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

24 Coenzyme: Vitamin B12 Most vitamins are coenzymes essential in helping move atoms between molecules in the formation of carbohydrates, fats, and proteins. Exclusively synthesized by bacteria. Dietary sources include meat, eggs, dairy products and supplements. Images: Streptomyces spores, Wiki; Vitamin B12 chemical structure, WikiStreptomyces sporesVitamin B12 chemical structure From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

25 Factors That Influence Enzyme Activity Temperature pH Cofactors & Coenzymes Inhibitors Image: Animation of Enzyme, WikiAnimation of Enzyme From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

26 Two Types of Enzyme Inhibitors 1. Competitive inhibitor inhibitor Chemicals that resemble an enzyme’s normal substrate and compete with it for the active site. Reversible depending on concentration of inhibitor and substrate. Image: Competitive inhibition of enzyme, Jerry Crimson MannCompetitive inhibition EXAMPLE: The drug Antabuse is used to help alcoholics quit drinking. Antabuse inhibits aldehyde oxidase, resulting in the accumulation of acetaldehyde (say a-si-’tell-de-hide) during the metabolism of alcohol. Elevated acetaldehyde levels cause symptoms of nausea and vomiting. From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

27 Two Types of Enzyme Inhibitors 2. Non- competitive inhibitor 2. Non- competitive inhibitor Do not enter active site, but bind to another part of the enzyme, causing the enzyme & active site to change shape. Usually r eversible, depending on concentration of inhibitor & substrate. EXAMPLE: You may know that compounds containing heavy metals such as lead, mercury, copper or silver are poisonous. This is because ions of these metals are non-competitive inhibitors for several enzymes. Image: Pouring liquid mercury, BionerdPouring liquid mercury Video Feedback Inhibition of a Metabolic Pathway From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

28 Enzyme Inhibitors B locking an enzyme's activity can kill a pathogen or correct a metabolic imbalance. Many medications are enzyme inhibitors. Enzyme inhibitors are also used as herbicides and pesticides. Images: Prescription bottle, T. Port; Dead cockroach, WikiDead cockroach EXAMPLE: Another example of competitive inhibition is protease inhibitors. They are a class of anti- retroviral drugs used to treat HIV. The structure of the drug ritonavir (say ri-TAHN-a-veer) resembles the substrate of HIV protease, an enzyme required for HIV to be made. From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

29 REVIEW! Enzyme Inhibition: 1. Enzyme Inhibition IEnzyme Inhibition I 2. Enzyme Inhibition IIEnzyme Inhibition II 3. Feedback InhibitionFeedback Inhibition of a Metabolic Pathway Image: Enzyme Inhibitor, WikiEnzyme Inhibitor, Q: What type of inhibition is this? From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

30 1. Meet the Enzyme : Catechol Oxidase Catechol oxidase (also called catecholase) is present in most fruits and vegetables. It is the enzyme that facilitates the browning of cut or bruised fruits and vegetables by catalyzing the following reaction. Reaction: catechol oxidase catechol + O  polyphenol colorless substrate brown product Image: Bananas & Apples, T. Port From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

31 1. Meet the Enzyme: Catechol Oxidase Reaction: catechol oxidase catechol + O  polyphenol colorless substrate brown product We can slow this reaction by removing the enzyme’s cofactor: Lemon juice and other acids are used to preserve color in fruit, particularly apples, by lowering the pH and removing the copper (cofactor) necessary for the enzyme to function.pH Images: Apples, T. Port; Lemons, André Karwath; Enzyme with Cofactor, Wiki; pH scale, Edward Stevens, WikiLemonsEnzyme with CofactorpH scale From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

32 1. Meet the Enzyme: Catechol Oxidase Reaction: catechol oxidase catechol + O  polyphenol colorless substrate brown product We can also slow this reaction by placing fruits & veggies under water. Q: Why would doing this prevent browning? From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

33 2. Meet the Enzyme: Catalase Reaction: catalase 2H 2 O  2H O 2 Catalase is an enzyme found in nearly all living things exposed to oxygen. This enzyme catalyzes the decomposition of hydrogen peroxide to water and oxygen, protecting the cell from oxidative damage. Images: Catalase test to determine if bacterial sample is aerobic, WikiCatalase test From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com Q: What do you think would happen if these potatoes were put into hydrogen peroxide, instead of water? Bacterial sample added to a hydrogen peroxide.. What are the bubbles made of?

34 3. Meet the Enzyme: Bromelain Pineapple contains enzyme bromelain, which can digest protein. (It is a protease.) Jell-O ® is made of gelatin, a processed version of a structural protein called collagen found in many animals, including humans.protein Collagen = big, fibrous molecule makes skin, bones, and tendons both strong and elastic. Gelatin you eat usually comes from the collagen found in cow, chicken or pig skin, bones and connective tissues. (Yummie!) Examine 2 containers: a. In one, canned pineapple was used to make Jell-O ®. b. The other, fresh pineapple was used. Q : Why is one Jell-O solid and the other liquid? Image: Pineapple, Whaldener EndoPineapple From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

35 3. Meet the Enzyme : Bromelain Reaction: bromelain collagen protein + H  amino acids substrate products Bromelain is a protease enzyme that facilitates hydrolysis of protein. enzyme Remember, hydrolysis cuts molecule by adding water…the reverse of the hydration synthesis pictured to the left. FYI: Bromelain is used as a meat tenderizer. Breaks down the collagen in meat. So what do you think could happen to your tongue when you eat fresh pineapple? From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com

36 Confused? Links to fun resources that further explain enzymes: Enzymes Main Page on the Virtual Cell Biology Classroom of Science Prof Online.Enzymes Science Prof Online “How Enzymes Work” an animation from McGraw-Hill.How Enzymes Work Interactive Enzyme Tutorial and quiz from Life: The Science of Biology.Interactive Enzyme Tutorial “ The Role Enzymes Play in the Body ” from Enzymedica. These guys are selling supplements. I don’t endorse the supplement, but their video is very instructive regarding enzymes and digestion. The Role Enzymes Play in the Body “ Assignment Discovery: Enzyme Catalysts ” from HowStuffWorks, a Discovery Company. Assignment Discovery: Enzyme Catalysts “ Enzymes and Digestion ” from About.com. Enzymes and Digestion Biochemical Pathways animation from McGraw Hill.Biochemical Pathways Activation Energy animation from Pearson Prentice Hall.Activation Energy Enzyme Hydrolysis of Sucrose animation from McGraw Hill.Enzyme Hydrolysis of Sucrose (You must be in PPT slideshow view to click on links.) From the Virtual Biology Classroom on ScienceProfOnline.comScienceProfOnline.com


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